#include <fstream>
#include <vector>

using namespace std;

ifstream in ("arbint.in");
ofstream out ("arbint.out");

class maxSegmentTree{
	int *data;
	int size;
	int n;
	void createVal(int left,int right,int position,vector<int> & v){ // function used by a constructor
		if(left==right){ // current node hold the number from v with index left
			data[position]=v[left-1]; // this is cleary its maximum
			return;
		}
		createVal(left,(left+right)/2,2*position,v); // we explore the left interval,mid interval
		createVal((left+right)/2+1,right,2*position+1,v); // we explore the mid+1,right interval
		data[position]=max(data[2*position],data[2*position+1]); // we set the maximum on the current interval based on previous explorations
	}
	int getMax(int left,int right,int a,int b,int position){ // we will find the maximum in the [a,b] 
		int result=-1; 
		int mid=(left+right)/2;
		if(left>=a&&right<=b)
			return data[position];
		if(mid<b){
			result=max(result,getMax(mid+1,right,a,b,2*position+1));
		}
		if(mid>=a){
			result=max(result,getMax(left,mid,a,b,2*position));
		}
		return result;
	}
	bool updateVal(int left,int right,int position,int index,int val){
		int mid=(left+right)/2;
		if(left==right && left==index){
			data[position]=val;
			return true;
		}
		if(mid>=index){
			updateVal(left,mid,2*position,index,val);
		}
		else{
			updateVal(mid+1,right,2*position+1,index,val);
		}
		data[position]=max(data[2*position],data[2*position+1]);
	}
public:
	maxSegmentTree(int x){
		n=x;
		int log,aux;
		//for(aux=1;aux<=n;aux<<=1,log++);
		//log--;
		log=8;
		data=new int[n*log];
		for(int i=1;i<n*log;++i){
			data[i]=-1;
		}
	}
	maxSegmentTree(vector<int> & v){
		n=v.size();
		int log=8;
		data=new int[n*log];
		createVal(1,n,1,v);		
	}
	int query(int l,int r){
		return getMax(1,n,l,r,1);
	}
	bool update(int position,int value){
		return updateVal(1,n,1,position,value);
	}
};

int main(){
	int n,m;
	maxSegmentTree *st;
	vector<int> v;
	in>>n>>m;
	int op,a,b;
	for(int i=1;i<=n;++i){
		in>>a;
		v.push_back(a);
	}
	st=new maxSegmentTree(v);
	for(int i=1;i<=m;++i){
		in>>op>>a>>b;
		if(op==0){
			out<<st->query(a,b)<<"\n";
			continue;
		}
		st->update(a,b);
	}
	return 0;
}